四倍率剪式抓斗在卸船机上的应用

抓斗广泛应用于港口、码头散料卸船时的作业,作为卸船机的关键部件,它的使用寿命、效率、维护性等各方面指标都会直接影响卸船作业的效率,影响港口、码头的正常运行。传统长撑杆双颚瓣抓斗进舱抓取作业时易形成散货陡坡,散货滑落易埋没抓斗,抓斗在散货陡坡作业易倾倒,与清舱设备发生碰撞等复杂工况,不适于卸船机散货自动化作业。以烟台港矿石码头为例,桥式卸船机应用四倍率剪式抓斗低重心防侧倾,效率高。结果表明:采用新式剪式抓斗自动化作业后,安全性、维护性、可靠性、作业效率都得到明显提升,可为实际生产应用提供参考。

ROUTE OPTIMIZING ALGORITHM OF AIRPORT SURFACE BASED ON GIS

The GIS technique is used for airport surface management to study the optimization of airplane taxiway for arrival and departure flights. The shortest paths are designed for just-arrived and ready-for-departing flights of the airport. Additionally, whether the flights could confront each other head-to-head on the taxiway is judged. In regard to the airport′s security and efficiency, airplanes must continuously taxi along the shortest route and the head-to-head confrontation should not occur. Two schemes are designed: One is to change the taxiing velocity of arrival flights, the other is to delay the starting time of departure flights. This algorithm is approved by a practical example.

Efficiency assessment of coal mine safety input by data envelopment analysis

In recent years improper allocation of safety input has prevailed in coal mines in China, which resulted in the frequent accidents in coal mining operation. A comprehensive assessment of the input efficiency of coal mine safety should lead to improved efficiency in the use of funds and management resources. This helps government and enterprise managers better understand how safety inputs are used and to optimize allocation of resources. Study on coal mine＇s efficiency assessment of safety input was con- ducted in this paper. A C^2R model with non-Archimedean infinitesimal vector based on output is established after consideration of the input characteristics and the model properties. An assessment of an operating mine was done using a specific set of input and output criteria. It is found that the safety input was efficient in 2002 and 2005 and was weakly efficient in 2003. However, the efficiency was relatively low in both 2001 and 2004. The safety input resources can be optimized and adjusted by means of projection theory. Such analysis shows that, on average in 2001 and 2004, 45% of the expended funds could have been saved. Likewise, 10% of the safety management and technical staff could have been eliminated and working hours devoted to safety could have been reduced by 12%. These conditions could have Riven the same results.

Development of coal store and transportation technology using horizontal coal bunker

Discussed the necessity of setting up the coal bunker in mining, introduced the development of coal bunker technology, combining the mining characteristic of the high yield and high-efficient working face in China at present, and point out that the type of horizontal coal bunker, is a kind of security, high-efficient coal store and transportation technology of suiting the modern production need of the colliery, is the developing direc-tion of technology of store and transportation of coal bunker.

Analysis of Evacuation Efficiency with Congestion Points in Large Sport Facilities

Large leisure activities usually use large sport facilities. There is often no serious problem with people gathering, but both incomplete facilities and negligence of people security manage may court injury or death. The purpose of this study is to analyze crowded nodes and to improve evacuation path use Simulex models. The fastest and safest way to achieve safe egress was then well planned. For turn locations, it was found that fixing the plane angle did not significantly raise the overall exiting efficiency. However, replacing the right angle or other angles with arc angle makes overall exiting moving line more fluent. For multito single-directional converging T-junction intersections, modification of turn angle increased the movement fluency, with the higher the modified angle, the higher in fluency. However, changing to round angle did not have as significant effect as expected while gate opening width must be increased to 1.0 m before more significant effects were produced. The results showed that modifying turn angles to 60° produces better improvements.

An energy efficiency clustering routing protocol for WSNs in confined area

Wireless sensor networks (WSNs) are important application for safety monitoring in underground coal mines, which are difficult to monitor due to natural conditions. Based on the characteristic of limited energy for WSNs in confined underground area such as coal face and laneway, we presents an energy- efficient clustering routing protocol based on weight (ECRPW) to prolong the lifetime of networks. ECRPW takes into consideration the nodes' residual energy during the election process of cluster heads. The constraint of distance threshold is used to optimize cluster scheme. Furthermore, the protocol also sets up a routing tree based on cluster heads' weight. The results show that ECRPW had better perfor- mance in energy consumption, death ratio of node and network lifetime.

A Public Verifiable Identity Based Signcryption in the Random Oracle Model

Since Libert and Quisquater's identity based signcryption scheme cannot provide public verifiability after research, the paper proposes a new identity based signcryption scheme. The scheme uses quadratic residue and pairings over elliptic curves to realize public verifiability. By analysis the scheme is proved to be more efficient than Libert and Quisquater's scheme. Moreover, a security proof of the original scheme is presented in the random oracle model.

超大电驱水平定向钻机在复杂地质与水文环境下超长对穿导向的技术运用

水平定向钻对穿导向技术可有效解决在导向钻进过程因距离长、地质与水文水质复杂带来导向施工精度、效率、安全、环保及经济性的问题。本工程运用高智能中控与良好力学性能的IHDD型超大电驱水平定向钻主钻机配一台辅助钻机再与双保险的先进导向测量系统相结合对穿导向的技术方法,其过程为主、辅助钻机分别钻进一定距离到达对穿位置节点,采用静态与动态相结合的方式实现对穿,而后把握节奏采用主钻机推进,辅助钻机同步后退的方式直至对接点出土,完成导向;该技术克服了打导向孔由于超长、复杂地质与水文带来的重重挑战,并验证了超大电驱水平钻机具有广泛运用前景的先例,在塘坂引水工程琅岐支线(马尾段)成功运用。

Privacy-preserving Distributed Location Proof Generating System

The rapid development of location-based service(LBS) drives one special kind of LBS, in which the service provider verifies user location before providing services. In distributed location proof generating schemes, preventing users from colluding with each other to create fake location proofs and protecting user's location privacy at the same time, are the main technical challenges to bring this kind of LBS into practical. Existing solutions tackle these challenges with low collusion-detecting efficiency and defected collusion-detecting method. We proposed two novel location proof generating schemes, which inversely utilized a secure secret-sharing scheme and a pseudonym scheme to settle these shortcomings. Our proposed solution resists and detects user collusion attacks in a more efficient and correct way. Meanwhile, we achieve a higher level of location privacy than that of previous work. The correctness and efficiency of our proposed solution is testified by intensive security analysis, performance analysis, as well as experiments and simulation results.

Analysis of STC Fault in Urban Rail Transit Station of Mobile Block System

Mobile block system is a new type of block technology based on the theory of interval block. This article focuses on the analysis of safety key points, the efficient use of emergency time, the maximum efficiency of mobilizers, to reduce the loss of emergency incidents and casualties.

Study of risk acceptance criteria for dams

This paper discusses the methods of establishing risk criteria for dams and reviews the application of dam risk criteria for individuals and societies in different countries or districts. Given the conditions in China and considering the public safety and acceptance of dam risk, historical dam break data and current design standards, individual and societal risk criteria for dams are proposed. The tolerable dam risk criteria for individuals should be set to 10-5-10-7 per annum based on project scale, for ex- ample, approximately 1.0xl0 7 per annum, which corresponds to a reliability index of 4.2 based on a 100-year lifespan for a first-class or large project. The societal limit for risk tolerance for dams should be set to approximately 10-3-10-5 per annum, corresponding to the fatality range from 1 to 100 and be horizontally extended to 1000, and F-N curves are proposed. It was also found that the reliability indices of Chinese Standard （GB 50199-2013） and Eurocodel （2002） are different, but they have the same level of safety measured by the annual probability of failure. The research results have significance for establishing dam risk criteria.

Chiglitazar monotherapy with sitagliptin as an active comparator in patients with type 2 diabetes:a randomized,double-blind,phase 3 trial(CMAS)

Chiglitazar(Carfloglitazar)is a novel peroxisome proliferator-activated receptor(PPAR)pan-agonist that has shown promising effects on glycemic control and lipid regulation in patients with type 2 diabetes.In this randomized phase 3 trial,we compared the efficacy and safety of chiglitazar with sitagliptin in patients with type 2 diabetes who had insufficient glycemic control despite a strict diet and exercise regimen.Eligible patients were randomized(1:1:1)to receive chiglitazar 32 mg(n=245),chiglitazar 48 mg(n=246),or sitagliptin 100 mg(n=248)once daily for 24 weeks.The primary endpoint was the change in glycosylated hemoglobin A_(1C)(HbA_(1c))from baseline at week 24 with the non-inferiority of chiglitazar over sitagliptin.Both chiglitazar and sitagliptin significantly reduced HbA1c at week 24 with values of-1.40%,-1.47%,and-1.39%for chiglitazar 32 mg,chiglitazar 48 mg,and sitagliptin 100 mg,respectively.Chiglitazar 32 and 48 mg were both non-inferior to sitagliptin 100 mg,with mean differences of-0.04%(95%confidential interval(Cl)-0.22 to 0.15)and-0.08%(95%Cl-0.27 to 0.10),respectively.Compared with sitagliptin,greater reduction in fasting and 2-h postprandial plasma glucose and fasting insulin was observed with chiglitazar.Overall adverse event rates were similar between the groups.A small increase in mild edema in the chiglitazar 48 mg group and slight weight gain in both chiglitazar groups were reported.The overall results demonstrated that chiglitazar possesses good efficacy and safety profile in patients with type 2 diabetes inadequately controlled with lifestyle interventions,thereby providing adequate supporting evidence for using this PPAR pan-agonist as a treatment option for type 2 diabetes.